Many wireless devices are equipped with multiple radio-access technologies (“RATs”) and are, therefore, capable of communicating over multiple wireless networks. For example, a device that is configured to communicate over a cellular network may also be configured to communicate over a wireless-access network, such as a wireless local area network. Recently, efforts have been made to develop mechanisms to balance traffic among multiple networks that are simultaneously available to a mobile device. For example, mobile operators sometimes provision a mobile device with radio-access network-selection parameters that the mobile device can use to select preferred networks to which it should connect or over which the mobile device should route certain traffic flows. A mobile device may receive such parameters from more than one network source, such as from a centralized network controller and from a base station within a cellular network. The mobile device then needs to determine which of the selection parameters it should use to evaluate the networks.